Terms and conditions

To assist his customers, fenestration product manufacturers and their stakeholders, in selecting the products according to the Canadian National Building Code, Provincial / Territorial / Municipal Building Codes, Energi has designed a Window Performance Grade Calculator.

It will allow you to establish the required performance grades for a specific building (based on geographic location, terrain conditions, building height & shape) in using the existing climate design data of more than 640 selected Canadian locations included in the 2010 National Building Code.

The calculator enables to determine the appropriate air tightness levels, the water penetration resistance as well as the positive / negative design pressure.

The results can be registered, classified and emailed.  An IPad application is also available.

This calculator is intended to manufacturers, architects, specifiers as well as consumers.


Our Window Performance Grade Calculator is intended solely to guide the window manufacturer, the consumer, the architect or specifier, when selecting a type of window product best appropriate for the conditions and geographic location in which the window will be installed.

Our Window Performance Grade Calculator has been developed in reference to Clause 4, Loads and Product Selection, of the Canadian Supplement to A440S1-09 - NAFS (North American Fenestration Standard/Specification for Windows, Doors and Skylights). The calculator uses the existing climate design data of more than 640 selected locations in Canada (Table A.1).

The designers and specifiers shall take into account that the specified loads are minimum performance requirements based on the geographic location.  When selecting a product, designers and specifiers should also consider local accepted good practice, demonstrated historical performance, and the specific conditions to which a particular window, door, or unit skylight will be exposed.

Furthermore, when selecting a product, the performance grade and water penetration resistance rating of windows, doors, and unit skylights shall be not less than the DP and specified DRWP to which the window, door, or unit skylight is expected to be exposed.